1. Technical Field
The present invention relates to: a traffic evaluation device for outputting traffic various quantities metrics on the basis of simulated running of a plurality of simulation vehicles; a computer program for realizing the traffic evaluation device; and a traffic evaluation method employing the traffic evaluation device.
2. Description of Related Art
As means of evaluating, in advance, influences caused by traffic restriction and the like, expectations for traffic simulators are growing and hence various engineering developments are carried out. In such traffic simulators, as input data, a traffic volume (e.g., an OD traffic volume) including origin and destination information of running of vehicles and traffic information such as running speeds and acceleration and deceleration characteristics of vehicles is treated as given. The OD traffic volume indicates a traffic volume obtained between the origin (the start point) and the destination of a vehicle. For example, statistical surveillance data or the like obtained as a result of statistical surveillance performed periodically by a state or a local government.
A purpose of a traffic simulator is to evaluate or estimate, in advance, influences arising after traffic environmental changes such as traffic restriction caused by a work, an accident, a disaster, or the like and a traffic environmental change such as new construction of a road and improvement in an intersection. Thus, the traffic simulator includes in advance a movement model for vehicles, that is, a formula simulating the behavior of vehicles, and then applies the above-mentioned input data into the formula so as to output traffic various quantities metrics such as a congestion length and a travel time in a road network containing isolated intersections, routes, city areas, and the like or alternatively environmental indicators such as carbon dioxide contained in the exhaust gas. In this case, the road network is constructed from a plurality of links (e.g., each is a road connecting an intersection to another intersection and having two directions of upbound and downbound) and nodes or the like (such as intersections) each of which is a point where links intersect with each other.
Specifically, on the basis of the inputted OD traffic volume, the traffic simulator calculates a generated traffic volume (a traffic volume that flows into the link) and a removed traffic volume (a traffic volume that flows out of the link) in each link of the road network. Then, the traffic simulator generates vehicles in a number corresponding to the generated traffic volume in each link and removes vehicles in a number corresponding to the removed traffic volume so as to calculate a congestion length and the like.
Further, a method is disclosed in which in a particular interval, by using the travel time of a particular vehicle obtained by vehicle sensors provided at both ends of the interval and the vehicle sensor data obtained in time series, the data on the time axis is projected onto the data on the space axis so that a congestion length is calculated (see Japanese Patent Application Laid-Open No. H08-161686).